Systemic granuloma in goldfish caused by a Dermocystidium-like aetiological agent

Abstract

Systemic infection by a Dermocystidium-like parasitic organism caused visceral granuloma and mortality in farmed qoldfish Carassius auratus. Granulomatous nodules occurred mainly in the kidney and spleen and later spread to other visceral organs. Macrophages within the granulomata contained 1 to 20 uninuclear or 1 plurinuclear parasite, sometimes located within a parasitophorous vacuole. The granulomata gradually became necrotic. Parasites were gradually displaced to the periphery and disappeared within 1 to 2 mo. The granulomata however, persisted and continued to expand after the elimination of the presumed aetiological agent. Granulomata regressed into fibrotic capsules 6 to 9 mo after disease onset.

Parasitism by Dermocystidium ranae in a population of Rana esculenta complex in Central Italy and description of Amphibiocystidium n. gen.

“…Dermocystidium infections have been previously reported in other European anurans: in Alytes obstetricans (Pérez 1913) (Pérez 1913, Poisson 1937). Yet other dermocystidians have been described from fish species, some of which are pathogenic (Cervinka et al 1974, Olson et al 1991, Landsberg & Paperna 1992, Wildgoose 1995.The parasite reported in the present paper is identical grossly, histopathologically and developmentally to Dermocystidium ranae, reported from Rana temporaria by Guyénot & Naville (1922). Bro= & Přívora (1951) also found D. ranae in R. temporaria, but reported spores with single-inclusion bodies, rather than the multiple granules reported from spores in the current paper.…”

“…Dermocystidium infections have been previously reported in other European anurans: in Alytes obstetricans (Pérez 1913) (Pérez 1913, Poisson 1937). Yet other dermocystidians have been described from fish species, some of which are pathogenic (Cervinka et al 1974, Olson et al 1991, Landsberg & Paperna 1992, Wildgoose 1995.…”

Infection of the kidney of Acanthopagrus australis (Pisces:Sparidae) with Sphaerospora sp. (Myxosporea), Prosorhynchus sp. (Digenea), and cysts of unknown origin

“…spores in the head and trunk kidney of A. australis were encapsulated and melanised, other agents may also cause the formation of TWC. Granulomatous reactions in the kidney of other fish have been attributed to various agents, for example, developn~ental stages of myxosporean parasites (Dykova et al 1987, Athanassopoulou & Sommerville 1993, Mycobacterium, Nocardia, bacterial kidney disease, fungi, deposits of metallic salts and organic compounds (Paperna 1979, Roberts 1989, Landsberg & Paperna 1992. There was no marked granulomatous reaction in the kidney of A. australis associated with any aetiological agent during the present study.…”

Ultrastructure of the aetiological agent of systemic granuloma in goldfish

“…Systemic granuloma in goldfish Carassius auratus has been reported from North America (Voelker et al 1977), Europe (Lom & Dykova 1992, Steinhagen et al 1993 and Israel (Landsberg & Paperna 1992). Large grey nodular lesions occur first in the kidneys and then spread to the spleen, while the liver is only mildly affected.…”

“…Histological examination has revealed granulomata with a necrotic core. In some fish, the granulomata are accompanied by numerous amoeboid organisms, in others, such organisms are few or entirely lacking (Landsberg & Paperna 1992). These organisms have been named 'Dermocystidium-like' (Landsberg & Paperna 1992), as have similar-looking organisms found to accompany systemic granulomatous conditions in salmonids (Hedrick et al 1989).…”